1. Field of the Invention
The present invention relates to an apparatus for transferring a movable body, and especially to an apparatus for loading a magnet-optical disc, an optical disc or the like into the inside of a disc player.
2. Description of the Related Art
With respect to a disc transfer apparatus for loading a cartridge such as a mini disc (MD) into the inside of a disc player, there have conventionally been known the rack-and-pinion type as shown in FIG. 15 and the lever type as shown in FIG. 16.
In the rack-and-pinion type, the power of a motor serving as the power source is transmitted to a pinion 101 through a reduction mechanism comprising a gear train. The pinion 101 drives a rack 102 so as to transfer a disc 103, which is connected to the rack 102.
In the lever type, a lever 104 is provided above a disc 103 so as to be swingable. The lever 104 is driven by a motor through a reduction mechanism comprising a gear train so as to transfer the disc 103, which is connected to front end of the lever 104.
The conventional rack-and-pinion type does not need any space for mechanical elements above the disc 103, thus permitting to reduce the height of a disc player. However, there is required a long distance L, which is identical with or more than twice as large as a stroke for transferring the disc 103. The conventional lever type permits to reduce the distance L. However, the installation of the lever 104 requires a space having a sector-shape above the disc 103, thus making it impossible to reduce the height of the disc player.
An object of the present invention is therefore to provide an apparatus for transferring a movable body, which has advantages of the rack-and-pinion type as well as the lever type, and more specifically, enables reduction, not only the height of a player, but also its depth.
In order to attain the aforementioned object, the rack-and-pinion type is applied to the apparatus of the present invention and a passage along which the driven rack moves is provided in its middle with a curved portion. More specifically, the apparatus for transferring a movable body comprises a rack having flexibility; a pinion for driving said rack; and a guide device for guiding said rack in movement thereof, said guide device having a curved portion.
Application of the rack-and-pinion type to the apparatus for transferring the movable body enables a reduction of the height of the player. The guide device for guiding the rack in its movement has the curved portion. As a result, the rack can curve in the passage for it in the middle, thus enabling a reduction in the depth of the player. The guide device may include a guide groove into which the rack is fitted, a guide shaft that pass through the rack and a guide rail.
The pinion may locate along the curved portion of the guide device. The pinion has conventionally been compelled to locate along the linear portion of the rack. According to the present invention, it is however possible to locate the pinion along the curved portion of the guide device, thus enabling improved degree of freedom in the placement of the pinion. When the passage for the rack is provided with the curved portion having a curve angle of about 90 degrees so that the passage is converted into an L-shape, placement of the pinion along the curved portion can avoid the existence of useless space and make the transfer apparatus small.
The rack may have a tooth shape having a smaller profile than a normal profile, which is adapted to the pinion. The normal profile means the involute tooth profile in case of the pinion having the involute tooth profile, on the one hand, and the cycloid tooth profile in case of the pinion having the cycloid tooth profile, on the other hand. According to such a structural feature, improper engagement of the pinion with the rack can be prevented when the pinion locates along the curved portion of the rack.
The rack may have engagement portions with the pinion, each of which has a triangular shape in a plan. According to such a structural feature, it is possible to manufacture easily the rack.
The guide device may comprise a guide groove, into which the rack is fitted, and at least part of the rack, which is received in the guide groove, may have a tooth profile that is formed into a block-shape so as to be guided smoothly in the guide groove. According to such a structural feature, the contact area of the tooth of the rack, which has the block-shape, with the wall surface of the guide groove becomes larger, thus permitting to guide the rack in a stable manner.
The guide groove may have a larger-width portion, which is larger than a height of the rack, and a smaller-width portion, which is smaller than the larger-width portion so as to ensure a proper engagement of the rack with the pinion. According to such a structural feature, the smaller width portion of the guide groove ensures a proper engagement of the rack with the pinion, on the one hand, and in the remaining portion other than the smaller width portion, i.e., the larger-width portion, the sufficient clearance between the guide groove and the rack causes the rack to move relative to the pinion, on the other hand. Accordingly, the proper drive of the rack can be ensured and the proper engagement of the rack with the pinion can also provided without subjecting the rack to a finishing treatment in its tooth profile in high accuracy.
The rack may locate so as to escape from a head of a player for the movable body in a plan. According to such a structural feature, it is possible to prevent interference of the rack with the head of the player, thus permitting to make the player in a smaller size. For example, when the mini disc (MD) is transferred, a magnetic writing head locates above the mini disc. The magnetic head moves in a perpendicular direction to a plan along which the mini disc is transferred. Placement of the rack to escape from the magnetic head in the plan reduces the height of the player.
The movable body may comprise a disc.
In order to attain the aforementioned object, an apparatus of the present invention for transferring a movable body, comprises a transfer lever for engaging with said recess portion to transfer said movable body, said transfer lever having a portion to be guided; and a guide device for guiding said portion to be guided of said transfer lever, said guide device being provided with a restriction member, in which movement of said portion to be guided is restricted unless said transfer lever moves by a prescribed amount of movement in a non-transferring state, and said prescribed amount of movement being determined to be smaller than an amount of movement required to cause said transfer lever to engage with said recess portion in the non-transferring state. According to the present invention, the depth of the recess portion of the movable body such as a disc, into which the transfer lever is to be fitted when the movable body is inserted into a receiving unit in an upside-down improper manner, is not identical with the depth of a recess portion of the movable body, into which the transfer lever is to be fitted when the movable body is inserted into the receiving unit in a proper manner. As a result, the transfer lever does not move so that an amount of its movement does not exceed the prescribed value in the former case. In this case, the movement of the portion to be guided is restricted by the restriction member of the guide device so that the movable body cannot be transferred. When the movable body is inserted into the receiving unit in the proper manner, the transfer lever moves so that an amount of its movement exceeds the prescribed value. As a result, the movement of the portion to be guided is not restricted by the restriction member of the guide device so that the movable body can be transferred.